Address Allocation Map Generator
Visualize occupied and available blocks.
Address Allocation Map Generator: inputs and results
Enter an IP address, CIDR prefix, or range. Then check its first and last address below.
Calculated Boundaries & ParametersReady
Key Capabilities
- •100% Client-Side: Zero telemetry or server latency.
- •RFC Compliant: Exact 32-bit and 128-bit integer precision.
- •Quick Copy: Instant access to CIDR, mask, and range bounds.
- •Cross-Platform: Works on desktop, tablet, and mobile browsers.
Related Planning, VLSM & CloudAll Tools
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Exact CIDR Aggregator
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Route Summary Calculator
Summarize networks and identify included gaps.
DHCP Scope Calculator
Plan allocation boundaries within a subnet.
How Address Allocation Map Generator Works?
This tool works by dividing a parent block into equal cells and coloring each cell as allocated or free, which turns an allocation list into a visual grid.
Enter the parent block
Type the block to map, such as
192.168.60.0/24.Choose the cell size
Pick the grid resolution, such as /28 cells (16 addresses each), which gives 16 cells.
Enter the allocations
Paste the allocated subnets with their names.
Render the map
Each cell is marked with the allocation that covers it, or as free.
Address Allocation Map Generator Formula
The formula is Cells = 2^(c − p), and Cell_k is allocated when Cell_k ∩ Allocation ≠ ∅.
Cell count
2^(c − p)c is the cell prefix, p is the parent prefix.
Cell start
Parent + k × 2^(32 − c)k from 0.
Cell status
allocated when it overlaps any allocationFree otherwise.
Used share
allocated cells ÷ total cells × 100 %At cell resolution.
Worked example: 192.168.60.0/24 in /28 cells
Cells = 2^(28 − 24) = 16 Allocations: Servers /26 (4 cells), Printers /28 (1), Wi-Fi /27 (2), Voice /26 (4) Allocated cells = 11 of 16 (68.75 %)
Address Allocation Map Generator Conversion Table
The table shows the 16 /28 cells of 192.168.60.0/24 and the allocation in each cell.
| Cell | Cell Prefix | Range | Status |
|---|---|---|---|
| 1 | 192.168.60.0/28 | .0 – .15 | Allocated: Servers |
| 2 | 192.168.60.16/28 | .16 – .31 | Allocated: Servers |
| 3 | 192.168.60.32/28 | .32 – .47 | Allocated: Servers |
| 4 | 192.168.60.48/28 | .48 – .63 | Allocated: Servers |
| 5 | 192.168.60.64/28 | .64 – .79 | Allocated: Printers |
| 6 | 192.168.60.80/28 | .80 – .95 | Free |
| 7 | 192.168.60.96/28 | .96 – .111 | Allocated: Wi-Fi |
| 8 | 192.168.60.112/28 | .112 – .127 | Allocated: Wi-Fi |
| 9 | 192.168.60.128/28 | .128 – .143 | Free |
| 10 | 192.168.60.144/28 | .144 – .159 | Free |
| 11 | 192.168.60.160/28 | .160 – .175 | Free |
| 12 | 192.168.60.176/28 | .176 – .191 | Free |
| 13 | 192.168.60.192/28 | .192 – .207 | Allocated: Voice |
| 14 | 192.168.60.208/28 | .208 – .223 | Allocated: Voice |
| 15 | 192.168.60.224/28 | .224 – .239 | Allocated: Voice |
| 16 | 192.168.60.240/28 | .240 – .255 | Allocated: Voice |
What is Address Allocation Map Generator?
The Address Allocation Map Generator is a tool that draws a grid of an address block, showing which parts are allocated and which are free.
Tables of subnets hide the shape of free space. A grid makes gaps, scattered fragments, and aligned free runs visible at a glance. In the example, the free cells at .80, .128 – .191 show where a /26 still fits.
Cell size sets the detail level. /28 cells suit a /24 parent, and /24 cells suit a /16 parent.
What are the uses of Address Allocation Map Generator?
There are 4 main uses of the Address Allocation Map Generator, including planning meetings, documentation, and fragmentation spotting.
Running planning meetings
A visual map shows stakeholders where new subnets fit.
Documenting sites
Site runbooks include an allocation map next to the subnet table.
Spotting fragmentation
Scattered free cells reveal space that needs consolidation.
Teaching address planning
Students see how VLSM fills a block from the start.